The Comparative Medicine Section (CMS) of the NIA is responsible for the well-being of research animals employed in the investigation of pertinent questions about the biology of aging. CMS responsibilities include, but are not limited to, the provision of housing and care that meets species-specific and age-specific needs and requirements. The CMS also aims to support NIA scientific research by providing training to investigators in the humane handling of these animals and the performance of experimental techniques. Furthermore, the CMS ensures that all animal research is conducted in compliance with NIA, NIH, and federal regulations and guidelines. The CMS works to establish firm, consistent resource management while maintaining a collaborative relationship with investigators. Technical assistance in the form of breeding management, sample collection, and experimental manipulations is available upon request. The CMS also provides mouse behavior phenotyping services to NIA investigators and holds a contract used by investigators to genotype their animals. Approximately 2700 samples/month are sent to the contractor. For investigators wishing to access the NIA vivarium, facility training must be completed prior to initial entry. CMS provided training includes facility access requirements, biosecurity measures, proper animal handling, relevant regulations, and other related issues. Updates in regulations or facility procedures are provided by the Animal Program Director (APD) at periodic Advisory Committee to the Animal Program (ACAP) meetings. The animal program, vivarium, and animal laboratory areas are inspected and evaluated twice a year by the NIA Animal Care and Use Committee (ACUC). These semi-annual reviews are conducted in accordance with federal regulations. In addition to these internal reviews, the animal program is assessed every three years by AAALAC (formerly the Association for the Assessment and Accreditation of Laboratory Animal Care, International), a private organization that promotes the humane treatment of animals in science. In June 2019 the NIA animal program was site visited by AAALAC. The outcome of the site visit is pending. CMS staff members assist with NIA IRP research projects and may conduct novel research with a focus on improving the health and welfare of animals in their care. CMS initiated projects aim to answer current questions in facility management and in the special needs and care of aging animals.